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A Delta Fiber
The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Jörn Lötsch – 1st expert on this subject based on the ideXlab platform
quick discriminAtion of A deltA And c Fiber mediAted pAin bAsed on three verbAl descriptorsPLOS ONE, 2010Co-Authors: Florian Beissner, Amadeus Brandau, Christian Henke, Lisa Felden, Ulf Baumgartner, Rolfdetlef Treede, Bruno G Oertel, Jörn LötschAbstract:
BAckground: A deltA And C Fibers Are the mAjor pAin-conducting nerve Fibers, ActivAte only pArtly the sAme brAin AreAs, And Are differently involved in pAin syndromes. Whether A stimulus excites predominAntly A deltA or C Fibers is A commonly Asked question in bAsic pAin reseArch but A quick test wAs lAcking so fAr. Methodology/PrincipAl Findings: Of 77 verbAl descriptors of pAin sensAtions, “pricking”, “dull” And “pressing” distinguished best (95% cAses correctly) between A deltA Fiber mediAted (punctAte pressure produced by meAns of von Frey hAirs) And C Fiber mediAted (blunt pressure) pAin, Applied to heAlthy volunteers in experiment 1. The sensAtion wAs Assigned to A deltA Fibers when “pricking” but neither “dull” nor “pressing” were chosen, And to C Fibers when the sum of the selections of “dull” or “pressing” wAs greAter thAn thAt of the selection of “pricking”. In experiment 2, with An independent cohort, the three-descriptor questionnAire Achieved sensitivity And specificity Above 0.95 for distinguishing Fiber preferentiAl non-mechAnicAl induced pAin (lAser heAt, exciting A deltA Fibers, And 5-Hz electric stimulAtion, exciting C Fibers). Conclusion: A three-item verbAl rAting test using the words “pricking”, “dull”, And “pressing” mAy provide sufficient informAtion to chArActerize A pAin sensAtion evoked by A physicAl stimulus As trAnsmitted viA A deltA or viA C Fibers. It meets the criteriA of A screening test by being eAsy to Administer, tAking little time, being comfortAble in hAndling, And inexpensive while providing high specificity for relevAnt informAtion.
PAin in the trigeminAl system: irritAtion of the nAsAl mucosA using short- And long-lAsting stimuliInternational Journal of Psychophysiology, 2003Co-Authors: Thomas Hummel, Parvaneh Mohammadian, Robert Marchl, Gerd Kobal, Jörn LötschAbstract:
AbstrAct The pAper describes methods which Allow intrAnAsAl irritAtion using short- And long-lAsting pAinful stimuli in humAns. Short-lAsting pAin is induced by gAseous CO 2 , while long-lAsting pAin is induced by A streAm of dry Air. Both models hAve been explored regArding their mAjor determinAnts, e.g. stimulus durAtion, stimulus intensity, or repeAted stimulAtion. Short-lAsting, non-inflAmmAtory pAin stimuli seem to provide specific indicAtors of A deltA –Fiber function, while responses to long-lAsting, inflAmmAtory pAin AppeAr to be indicAtive of C-Fiber function. Responses to both types of pAinful stimuli Are modulAted by AnAlgesic drugs. As these well-investigAted models Allow the detAiled And precise AnAlysis of modulAtory effects on intrAnAsAl nociception, they AppeAr to be suited for the investigAtion of subtle chAnges of intrAnAsAl irritAtion, e.g. induced by environmentAl Agents.
Hitoshi Kontani – 2nd expert on this subject based on the ideXlab platform
sepArAte recording of A deltA And c Fiber mediAted nociceptive flexor reflex responses of mouse hindlimb using electromyogrAphy And the chArActeristics of wind up AppeAring in the responsesJournal of Pharmacological Sciences, 2008Co-Authors: Satoko Kimura, Hitoshi KontaniAbstract:
AbstrAct To meAsure sepArAtely electromyogrAm (EMG) Activity of A-deltA And C Fiber– mediAted responses And study the chArActeristics of drug effects on them in mice, we modified our originAl method designed to meAsure these responses AssociAted with hindlimb withdrAwAl movements. Single electricAl stimulAtion Applied to the toe elicited biphAsic EMG Activity in the ipsilAterAl femoris biceps muscle And withdrAwAl movement. Times to peAk of the short- And long-lAtency response of EMG Activity were Almost consistent with those obtAined from the hindlimb movement. As the short- And the long-lAtency responses of EMG Activity were selectively inhibited by tetrodotoxin (TTX) (3 And 10 μM) And cApsAicin (0.98 And 3. 27 mM) Applied to the sciAtic nerve, the responses were considered to occur viA A-deltA And C Fibers, respectively. A 0.5-Hz repetitive conditioning stimulus (CS) elicited significAnt wind-up in both the A-deltA And C Fiber–mediAted responses. The wind-up of the A-deltA Fiber–mediAted response disAppeAred during the CS And thAt of the C Fiber–mediAted response continued throughout the CS. This method is simple but useful for studying the effect of AnAlgesic Agents on A-deltA And C Fiber–mediAted nociceptive responses And clArifying the roles of these Afferent Fibers in chronic pAin in mice.
John Ravey – 3rd expert on this subject based on the ideXlab platform
effects of electric stimulAtion on c And A deltA Fiber mediAted thermAl perception thresholdsArchives of Physical Medicine and Rehabilitation, 2004Co-Authors: Shea Palmer, Denis Martin, W M Steedman, John RaveyAbstract:
AbstrAct PAlmer ST, MArtin DJ, SteedmAn WM, RAvey J. Effects of electric stimulAtion on C And A deltA Fiber-mediAted thermAl perception thresholds. Arch Phys Med RehAbil 2004;85:119–28. Objective To determine if interferentiAl current (IFC) or trAnscutAneous electric nerve stimulAtion (TENS) Alters C And A deltA Fiber-mediAted thermAl perception thresholds. Design Single-blind, rAndomized controlled triAl. Setting LAborAtory. PArticipAnts One hundred forty heAlthy women volunteers (meAn Age ± stAndArd deviAtion, 20.6±2.7y). Interventions Subjects were rAndomly And exclusively Assigned to 1 of 7 groups (n=20 in eAch): 0, 5, And 100Hz of IFC; 5 And 100Hz of TENS; plAcebo And control stimulAtion. StimulAtion wAs Applied through 2 electrodes plAced over the mediAn nerve. WArm sensAtion, cold sensAtion, hot pAin, And cold pAin perception thresholds were meAsured from the thenAr eminence by using A quAntitAtive sensory testing device And A method of limits Algorithm. MAin outcome meAsures WArm sensAtion, cold sensAtion, hot pAin, And cold pAin thresholds (°C) before, during, And After stimulAtion. Results There wAs A stAtisticAlly significAnt effect of time for All 4 thermAl perception thresholds (sepArAte 2-wAy AnAlyses of vAriAnce with repeAted meAsures, All P P >.05). Conclusions Neither IFC nor TENS Altered C And A deltA Fiber-mediAted thermAl perception thresholds. The results suggest thAt Any AnAlgesic mechAnisms with these modAlities Are likely to be complex.